into butyric acid and carbon dioxi$£. *|Vl\en the effervesce begins to slacken, decant the gas^mvn^ tube of lime-water, shake up and noti^,tIife'Vi@^t)0 fTfe acid which remains will have a strong smeTT"^^ C2H6CH(CO3H)2 = C3H7CO.OH + C02 See Appendix, p. 256. Chloral Hydrate, CC13.C Liebig, Annalen, 1832, 1, 189; Dumas, Aim. Chim. Phys. 1834, 56, 123. Chloral hydrate is obtained by the action of chlorine upon ethyl alcohol. The solid chloral alcoholate is formed, CC13.CHOH.OC.2H5, which, when decomposed with sulphuric acid, yields chloral, CC13.COH, a liquid which combines with water to form the crystalline hy'drate. Properties.—It crystallises in prisms, which dissolve easily in water, alcohol, and liquid hydrocarbons. It has a peculiar smell ; m. p. 57°; b. p. 97*5°. It volatilises on evaporating its aqueous solution. Reactions.—i. Add a few drops of a solution of chloral hydrate to a little ammonio-silver nitrate solution and warm. Metallic silver will be deposited. 2. Add a little caustic soda to a solution of chloral and warm gently. The heat of the hand is sufficient for the purpose. A smell of chloroform is at once apparent, CC13.CH(OH)2 + NaOH==CHCl3 + HCO.ONa-hH.,O. Sodium formate remains in solution. 3. Add a few drops of ammonium sulphide solution and warm gently. A brown colouration or precipitate is formed. PREPARATION 24. Trichloracetic Acid, CC13,CO.OH. Dumas, Compt. rend., 1838, 8, 609 ; Clermont, Ann. ChiiiL PAvs., 1871, (6), 6, 135- 25 grms. chloral hydrate 20 3, fuming nitric acid ; sp. gr. 1 '5 (see p. id).